Alkylation process



Patented Sept. 15, 1953 Warren W.

Johnstone, Riverside, 111;, asslgnor to Universal Oil'Products Company,

Chicago, lit,

a corporation of Delaware No Drawing. Application J une 13, 195-1,Serial. No. 231,422

12- Claims.

1 This invention relates to an alkylationprocess effected in thepresence of a novel catalyst dis;- closed for polymerization. in mycopending application S. N. 757,065 filed June 25 1947, now

U. S. Patent No. 2,559,576, issued July 3, I951. It is more particularlyconcerned withthecatalytic alkylation of aromatic compounds;

An object of this invention, is to produce an alkylated organiccompound, and particularly an alkylated aromatic hydrocarbon.

Another object of this invention is to react an alkylatable compound andan olefin-acting compound in the presence of a. novel catalyst- Oneembodiment of this invention relates to a process which comprisesreacting an alkylatable compound and an olefin-acting. compound atalkylating conditionsin the presence of a catalyst formed by reactingphosphoruspentoxide and boric acid.

Another embodiment of this invention relates to a process whichcomprises reactingan alkylatable hydrocarbon and an olefin-actingcompound at alkylating conditions in the presence of a catalyst formedby reacting phosphorus. pentoxide and boric acid] A further embodimentof this invention relates to a process which comprises reacting analkylatable aromatic compound and an Olefinacting compound at alkylatingconditions in the presence of a catalyst formed by reactingphosphoruspentoxide and boricacid.

A still further embodiment Of this invention relates to a process whichcomprises reacting an aromatic hydrocarbon having a replaceable nuclearhydrogen atom and an olefin-acting compound at, alkylating conditions inthepresence of a catalyst formed by reacting phosphorus pentoxide andboric acid. 7

An additional embodiment of this inventionrelates to a process which"comprises reactinga benzene hydrocarbon having a 'repl'aceable'nuclearhydrogen atom and an olefini'c hydrocarbon at alkylating conditions inthe presence'of'a catalyst formed by reacting phosphorus pentoxide andboric acid.

A still additional embodiment of'this invention relates to a process forproducing an alk-ylated benzene hydrocarbon whichcomprises reactingbenzene and a monoolefin at an'alkylation temperature and pressure inthepresence of and recovering the resultant alkylated benzene hydrocarbon.

Alkylatable compounds which may be usedas starting materials in thisprocess comprise .hy

drocarbons, hydroxy hydrocarbons, and} the like. The hydrocarbonsinclude both; branchedchain alkanes. and cyclic hydrocarbons, thepreferred cyclic hydrocarbons being those ofthe aromatic series. Thearomatic hydrocarbons including benzene hydrocarbons such as benzene,toluene, the xylenes, ethylbenzene and other alkylbenzenes containing atleast 1 replaceable nuclear hydrogen atom. Polycyclic aromatichydrocarbons such as naphthalene, alkyl' naphthalenes and other polynuclear hydrocarbons which contain at least 1 replaceable nuclearhydrogen atom are also alkylated by olefinracting compounds as hereinset forth. The hydroxy hydrocarbons in,- clude particularly the phenols,naphthols and other hydroxy aromatic hydrocarbons, includingmono-hydroxy and polyhydroxy aromatic hydrocarbons, an example 01 thelatter being hydroquinone. The, aromatic hydrocarbons, including thebenzene hydrocarbonsmaybeobtained from any source such as by thedistillation of coal; by the dehydrogenation of'naphthalenichydrocarbons, by the cyclization of aliphatic hydrocarbonsand by othermeans. The cyclic hydrocarbons also include alkylatable cycloparaflinssuch as alkylcyclopentane and alkylcycl h x ne hydrocarbons. Branchedchain paraflins such as isobutane, isopentane and. other branchedcha 1-kanes may also be charged, to the alkylation treatment as hereinsetforth.

Suitable alkylating. agents which may be charged in this process areolefin-acting compounds including monoolefinadiolefins, .polyole fins,also alcohols, ethers, esters, the latter including alkyl halides, alkylphosphates. certain alkyl sulfates and also esters of various. or anicarboxylic acids. The preferredalkylatingagents are olefinichydrocarbons which cpmprise ,mono olefins having one double bondpermQleculeend polyolefins which have, more than one double bond permolecule. Monoolefins-which maybe utilized for alkylatingaromatichydrocarbons andother alkylatable compounds in the presence of,aboro phosphoric acidcatalystare either normally aseous or normallyliquid and include ethylene, propyl n butylenes. p ntenes. and, higher.norma ly liquid olefins, the later including various polymers of gaseousoleiins, particularly Polymers having frame to.l8-carbon,atoms.permolecule. Cycloolefins such as cyclopentene, .cyclohexene, and variousalkylcycloolefins mayalsobe used. Other unsaturated hydrocarbons.usedasalkillating agents in this process include conjugated Q1:-olefins such as butadiene and isoprene, non-conjugated :idiolefins,other polyolefin hydrocarbons containing more than two double bonds permolecule, terpenic hydrocarbons, etc.

The catalyst employed in this process is prepared conveniently by mixingpowdered phosphorous pentoxide and powdered boric acid and addingthereto a small amount of water. The addition of water initiates areaction that is accompanied by the evolution of fumes. The resultantmixture is slightly moist, but after drying at 95-100 C., it is dry andnonhygroscopic. A substantial portion of the material appears tocorrespond to the formula B4O1 H3P2Oe)2, which may be calledtetraborohypophosphoric acid.

The process of this invention may be carried out in batch operation byplacing an alkylatable compound and the reaction product of phosphoruspentoxide and boric acid, which is regarded as tetraborohypophosphoricacid, in an autoclave and stirring while an olefin hydrocarbon is addedgradually thereto, the reaction mixture being maintained at an elevatedtemperature at which alkylation of the benzene hydrocarbon takes place.After the reaction has occurred, the reactor is then cooled and thealkylation product is recovered from the resultant reaction mixture.

It is preferred, however, to carry out this process in a continuousmanner. This may be accomplished by placing a fixed bed of catalystwithin a reactor such as a steel tube and the reactants, that is, thealkylatable compound and the olefin-acting compound are then passedcontinuously through the bed of catalyst at alkylation conditions. Thealkylation product is then recovered from the reactor efiluent and anyunreacted alkylatable compound and olefin-acting compound may then berecycled to the reaction zone. Fluidized type of operation may also beemployed in the catalyst. In this method of operation, a charging stockis passed upwardly through a bed of finely divided catalyst causing thecatalyst particles to become set in motion and form a fiuidlike mass.Inasmuch as the alkylation reaction is exothermic, a portion of thecatalyst may be l; withdrawn from the reaction zone eitherintermittently or continuously, the withdrawn catalyst is cooled andthen returned to the reaction zone in order to provide a convenientmethod of temperature control. Another mode of operation which may beemployed is the moving bed type of operation wherein a compact bed ofthe catalyst is passed continuously through the reaction zone eitherconcurrently or countercurrently to the incoming reactants, the catalystis then passed into a cooling zone from which it is returned to thereaction zone. Another alternative type of operation comprisessuspending finely divided solid catalyst in a stream of charging stocktreating said suspension under suitable conditions of temperature andpressure to produce the desired alkylation reaction.

The temperature at which the alkylation process of this invention may beconducted is dependent upon the charging stocks being employed. However,the alkylation process is generally carried out at a temperature of fromabout 100 C. to about 400 C. and preferably at a temperature of fromabout 150 C. to about 300 C. Pressure aids the reaction of alkylationand consequently this process is preferably effected at asuperatmospheric pressure-which is generally not in excess of about 200atmospheres.

4 drocarbons, an olefin-acting compound, an olefin-containinghydrocarbon fraction, or other olefin-acting compound may be commingledwith a reacting aromatic compound so that the ratio of alkylatablecompound to olefin-acting compound in a total mixture charged to thealkylation zone is approximately 5:1 on a molar basis. In some casesthis molar ratio of alkylatable compound to olefin may be as low asabout 1:1 or as high as 10:1 or even :1, the exact ratio being dependentsomewhat on the particularly alkylatable compound and olefinichydrocarbon or other olefin-acting material charged to the process.

Alkylated compounds formed in this process may be used as intermediatesfor organic synthesis or utilized for other purposes. Thus alkylatedaromatic hydrocarbons which are formed from benzene and olefins or fromother aromatic hydrocarbons and olefins are useful as starting materialsin the production of detergents, insecticides, synthetic rubber, etc.Also certain alkylated hydrocarbons are valuable as motor fuelconstituents because of their relatively high octane numbers.

The following examples are given to illustrate this invention but theyare introduced with no intention of limiting unduly the generally broadscope of the invention.

Example I A borophosphoric acid catalyst was prepared as follows: Fiftygrams of reagent grade boric acid was ground to a powder in a mortar andwas then presence of the aforementioned and In carrying out thealkylation of aromatic transferred to a large evaporating dish. Fiftysixgrams of finely powdered reagent phosphorus pentoxide was then added tothe evaporating dish and the materials therein were intimately mixed bystirring with a glass rod for 0.5 hour. The mixture was then pyramidedand a few drops of distilled water were added at the apex. A vigorousreaction ensued followed by the evolution of fumes. ihe wetborophosphoric acid thus produced was then dried overnight in an oven atC. The next morning it was weighed and ground to a powder. The weight ofthe borophosphoric acid was 93.3 grams. Prior to grinding theborophosphoric acid was gray, but after it had been powdered, it waswhite.

Example II The borophosphoric acid catalyst prepared as described inExample I is used to catalyze the alkylation of benzene-with propylenein an autoclave at a temperature of 275 C. and at a pres,- sure of 175atmospheres. In this run grams of benzene and 25 grams oftetraborohypophosphoric acid are mixed withstirring in an autoclave'atthe reaction temperature while 50 grams of propylene is introducedthereto during a time of 30 minutes. The reaction mixture is thenstirred at its self-generated pressure for an additional time of 1 hourafter which the autoclave and contents are cooled to 25 C. Conversion ofthe propylene is found to be substantially complete and the reactionmixture is found to contain 0.8 mol of isopropyl benzene and 0.2 mol ofdiisopropyl benzene.

I claim asmy invention:

1. A process which comprises reacting an alkylatable compound and analkylating agent at alkylating conditions in the presence of a catalystcomprising B407(H3P206)2- 2. A process which comprises reacting analkylatable.hydrocarbonrand an alkylating agent at alkylating conditionsin the presence of a catalyst comprising B407(H3P20c)2.

3. A process which comprises reacting an alklatable aromatic compoundand an alkylating agent at alkylating conditions in the presence of acatalyst comprising B4O7(H3P2O@)z.

4. A process which comprises reacting an aromatic hydrocarbon having areplaceable nuclear hydrogen atom and an olefin at alkylating conditionsin the presence of a catalyst comprising B407 (HsPzOc) 2.

5. A process which comprises reacting a benzene hydrocarbon having areplaceable nuclear hydrogen atom and an olefinic hydrocarbon atalkylating conditions in the presence of a catalyst comprisingB407(H3P206) 2.

6. A process for producing an alkylated benzene hydrocarbon whichcomprises reacting benzene and a monolefin at an alkylation temperatureand pressure in the presence of B407 (HsPzOc) 2 and recovering theresultant alkylated benzene hydrocarbon.

7. A process which comprises reacting a benzene hydrocarbon having areplaceable nuclear hydrogen atom with a monoolefin at a temperature offrom about to about 400 C. in the presence of a catalyst comprisingB4O7(H3P2O6) 2.

8. The process defined in claim 7 further characterized in that themonoolefin comprises ethylene.

9. The process defined in claim 7 further charterized in that monoolefincomprises propylene.

10. The process defined in claim 7 further characterized in that themonoolefin comprises a butylene.

11. The process defined in claim 7 further characterized in that themonoolefin comprises a pentene.

12. The process defined in claim 7 further characterized in that themonoolefin comprises a monoolefin polymer having from 6 to 18 carbonatoms per molecule.

WARREN W. JO-HNSTONE.

References Cited in the file of this patent UNITED STATES PATENTS Number

4. A PROCESS WHICH COMPRISES REACTING AN AROMATIC HYDROCARBON HAVING AREPLACEABLE NUCLEAR HYDROGEN ATOM AND AN OLEFIN AT ALKYLATING CONDITIONSIN THE PESENCE OF A CATALYST COMPRISING B4O7(H3P2O6)2.